The current manufacturers of small sized springs are mostly processed by cold drawing to the desired size under a room temperature and then tempering to increase the elastic character. This is processed in a heat furnace, and the small springs are collected in a container after the heat treatment and kept in the room temperature to cool down the temperature of the springs. This therefore can be referred as a `heat furnace`. The temperature of this `heat furnace` can not be controlled which causes a poor quality product.